A variety of materials, delivered in numerous configurations, have been used for the management of liquid spills in manufacturing environments. These materials include granular absorbents, sheet and roll goods, and boom configurations consisting of a casing filled with particulate sorbent products such as clay, cellulose, chopped corn cobs, or chopped microfibrous materials. Several types of sorbent products are typically used at location because no one sorbent product is adaptable to the many spill situations encountered in a manufacturing environment.
Historically, loose granular clay particles have been the principal material used for spill management activities in a manufacturing environment. Clay particles were preferred because they were economical, capable of sorbing both oil or water based spills, easily applied to a spill and readily adaptable to a variety of situations such as spills on irregular surfaces or in minimal clearance situations (i.e., under machines). In spite of these advantages, clay particles have disadvantages in that they are easily tracked to locations adjacent the spill site and the cleanup operation is labor intensive, requiring brooms, shovels, dustpans and a variety of containment vessels.
The use of loose granular materials has been declining with the introduction of "dimensioned" sorbent articles, i.e., sheets or rolls of sorbent materials or booms consisting of porous casings which are filled with loose granular sorbent materials. Dimensioned sorbent articles offer the convenience of easy placement, the ability to deliver a larger mass of sorbent material to the spill site in a smaller volume than would be required with loose materials, less mess than loose granular materials and a cleanup that is considerably less labor intensive than with loose granular materials.
The liquid holding capacity of sorbent articles used in spill management activities is an important factor in the selection of sorbent articles as it is desirable to contain, remove and recover spilled liquids using the minimum amount of sorbent material. Equally important, however, is the rate at which the sorbent article picks up or sorbs the liquid spill. Rapid, high capacity pickup of a liquid spill provides improved safety and higher productivity in a manufacturing environment by reducing exposure to the spill and the time required for spill management activities.
U.S. Pat. No. 4,965,129 (Bair et al.) discloses a sausage-shaped liquid-absorbing article which includes within a porous fabric, fine, fibrous particles of flash spun polyethylene, optionally particles of foamed organic polymer, and an effective amount of a wetting agent. The article is capable of absorbing oils or aqueous liquids in amounts equal to at least six times the weight of the particles.
U.S. Pat. No. 4,792,399 (Haney et. al.) describes a liquid collecting and retaining device consisting of a tubular, triangular shaped casing of a material which is permeable to liquids, which is partially filled with a material that collects and retains liquids passing through the casing, and which is incapable of itself passing through the casing.
U.S. Pat. No. 4,840,734 (Johnson) discloses a product for absorbing liquid leaks and spills which includes at least one closed cell with a cell wall permeable to liquid. An inorganic, inert absorbent is enclosed within the cell. Liquid contacting the product will pass through the cell wall and will be absorbed by the absorbent. A process for absorbing liquid leaks and spills is also provided.
U.S. Pat. No. 4,775,473 (Johnson et. al.) describes an absorbent article suitable for the absorption of aqueous as well as oleaginous liquids such as metal cutting fluids, hydraulic fluids, oils, and the like. The absorbent article is a spunlaced material sleeve closed at both ends and filled with an inherently flameproof particulate material, such as particulate clay material, having a certain particle size range. The spun laced material is liquid permeable, oleophilic and hydrophilic. The spunlaced material also has a liquid wicking rate that is at least equal to that of the particulate clay material contained within the sleeve. Preferred spunlaced materials are woodpulp/polyester spunlaced materials having a woodpulp-rich face and a polyester-rich face. The polyester-rich face is situated contiguous to the particulate absorbent material.
U.S. Pat. No. 4,659,478 (Stapelfeld) discloses an oil absorbing member and method which includes an elongate tubular member filled with a highly absorbent particulate material of capillary nature having a wicking action. The tubular member is closed at each end and can be arranged around a machine tool base as a continuous absorbing member.
In addition to the above referenced patents, there are a number of commercially available spill containment and recovery articles. For example, 3M Company, St. Paul, MN, sells a family of liquid sorbent articles designed to contain and recover liquid spills. These articles, which are based on sorbent microfibrous materials, include sheet goods for wiping and final cleanup operations, pillows designed for intermediate quantity liquid recovery, and booms, consisting of chopped microfibrous materials contained within an elongate casing having a substantially circular cross-section, which are used to contain and recover larger volume spills. These materials are described, for example, in 3M product bulletin "Maintenance Sorbents" No. 70-0704-0625-4(227.5) DPI.